CHICOPEE, Mass. (WWLP) – Western Massachusetts is in a heat wave, and close to historical record highs.

The hottest temperature recorded at Westover Air Reserve Base in Chicopee is 102 degrees on June 26, 1952.

Why is it so hot?

First, the jet stream is dragging in hot, humid air from the southwest. We also have an area of high pressure in the upper levels of the atmosphere. Simply put, high pressure leads to sinking air, which compresses the air at the surface. When air is compressed, it heats up.

There’s one over the Pacific Northwest which is why they are shattering records. But we also have one here on the east coast that’s bringing its own extreme heat and humidity.


The shape in the jet stream, which looks like the Greek letter Omega, is called an Omega Block and that can cause these heat domes to become stalled.

The heat wave began on Sunday with our first 90-degree high temperature. It continued Monday with a high of 96 which is only one degree shy of the record, and it will likely continue into Wednesday.

Climate change does play a part. A small shift in average temperatures leads to a much larger shift in extremes, and this second heat wave of the year is an example of that.